As blade driving devices for cameras, shutter devices, stop devices, filter devices, and lens barrier devices are known. However, it is common practice that any of these devices is located proximate to a photographic lens, with the exception of a focal plane shutter of the shutter devices. Formerly, the photographic lens has been placed at about the middle of a camera body, viewed from to the object side. Hence, as set forth in Japanese Patent Kokai No. 2004-264467, constituent members of the blade driving device can be arranged in such a way as to surround the optical axis and thus the number of degrees of design freedom is increased.
However, variously designed cameras have recently been appeared, and cameras in which the photographic lens is placed at the end or corner of the camera body, viewed from the object side, have also been appeared. Cameras incorporated in information terminals, such as mobile phones, PDAs, or PCs, are such that the photographic lens is generally placed at the end or corner of each of these terminals. However, it is very difficult that the blade driving device is constructed so that it is capable of accommodating such a placement. The maximum reason for this is that it is difficult to ensure space for the arrangement of blades where they are removed from a photographing optical path.
Under such circumstances, a shutter device of an interesting structure is disclosed in Japanese Patent Kokai No. 2005-287159. According to this reference, the shutter device is provided with two shutter blades designed so that they are reciprocated and rotated in opposite directions at the same time. A shutter base plate is nearly elongate and the two shutter blades are constructed so that each of them is rotatably mounted in a region between one end of the shutter base plate in its longitudinal direction and an opening for the photographing optical path and when an opening operation is performed, one shutter blade, although in a rotational motion, is operated toward about the longitudinal direction of the shutter base plate which is the direction of its mounting region, while the other shutter blade also, although in a rotational motion, is operated toward one region of the shutter base plate in about its lateral direction.
The shutter device constructed as mentioned above is convenient for placement in a limited-width space because the shutter base plate is nearly rectangular. In addition, it is possible that the shutter device is constructed so that a region on the opposite side of the mounting region, of the shutter blades, that is, a region between the other end of the shutter base plate in its longitudinal direction and the opening for the photographing optical path, is made small and the opening for the photographing optical path is brought close to the other end side. Hence, the shutter device constructed as mentioned above is easily used in the camera in which the photographic lens is placed at the end or corner of the camera body or the information terminal. The present invention relates to the blade driving device for cameras further developing such a structure.